The personal care industry strives to deliver multiple performance products based on mixtures of several components each having performance characteristics important to or desirable in the final formulation. One desirable characteristic is the ability to provide an initial silky feel. This property can be conferred by cyclic siloxanes such as octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane. Although cyclic siloxanes provide the desirable feel characteristics, they are low viscosity and highly flowable liquids. Therefore, they are not readily retained within a formulation preferring rather to separate within a package unit or flow in an uncontrollable manner across the skin upon application.
Known types of polyorganosiloxane gels have been found to deliver the desirable initial silky feel of cyclic siloxanes but unlike the latter, possess viscosities that are high enough to prevent their separation or uncontrollable flow. In addition to providing an initial silky feel, known polyorganosiloxane gels impart to personal care compositions the further desirable quality of producing a smooth silky sensation on dry-down. Such polyorganosiloxane gels are made by the hydrosilylation of ethylenically unsaturated, e.g., vinyl group-containing, polyorganosiloxane by hydrogen polyorganosiloxane in an oil-in-water (O/W) emulsion reaction medium employing a precious metal hydrosilylation catalyst, e.g., a platinum-containing catalyst such as chloroplatinic acid or Karstedt's catalyst (organoplatinum coordination complex). This process produces polyorganosiloxane O/W gel emulsions containing hydrosilylated reaction product(s) exhibiting moderate crosslinking and as a result, moderate levels of storage modulus (G′) and relatively high swelling in organic solvent.